major: build islands + scan routeDir without importing user code

This fixes a bunch of long standing issues in our tracker where a build
wouldn't finish because of importing user code. It's common for backend
apps to spawn some open ended tasks like subscribing to Deno KV or other
things. This addresses another problem of having to set up ENV vars just
for the build, even though they are technically not required to build
islands.

This also gives a roughly ~30% performance boost on cold starts.

Author: marvinhagemeister

deno.json

@@ -14,7 +14,8 @@
     ".": "./src/mod.ts",
     "./runtime": "./src/runtime/shared.ts",
     "./dev": "./src/dev/mod.ts",
-    "./compat": "./src/compat.ts"
+    "./compat": "./src/compat.ts",
+    "./do-not-use": "./src/internals.ts"
   },
   "tasks": {
     "test": "deno test -A --parallel",

init/src/init.ts

@@ -349,7 +349,7 @@ ${GRADIENT_CSS}`;
     // Skip this and be silent if there is a network issue.
   }
 
-  const MAIN_TS = `import { App, fsRoutes, staticFiles } from "fresh";
+  const MAIN_TS = `import { App, staticFiles } from "fresh";
 import { define, type State } from "./utils.ts";
 
 export const app = new App<State>();
@@ -371,10 +371,8 @@ const exampleLoggerMiddleware = define.middleware((ctx) => {
 });
 app.use(exampleLoggerMiddleware);
 
-await fsRoutes(app, {
-  loadIsland: (path) => import(\`./islands/\${path}\`),
-  loadRoute: (path) => import(\`./routes/\${path}\`),
-});
+// Include file-system based routes here
+app.fsRoutes();
 
 if (import.meta.main) {
   await app.listen();
@@ -489,14 +487,13 @@ export default function Counter(props: CounterProps) {
   const DEV_TS = `#!/usr/bin/env -S deno run -A --watch=static/,routes/
 ${useTailwind ? `import { tailwind } from "@fresh/plugin-tailwind";\n` : ""}
 import { Builder } from "fresh/dev";
-import { app } from "./main.ts";
 
 const builder = new Builder();
-${useTailwind ? "tailwind(builder, app);" : ""}
+${useTailwind ? "tailwind(builder);" : ""}
 if (Deno.args.includes("build")) {
-  await builder.build(app);
+  await builder.build();
 } else {
-  await builder.listen(app);
+  await builder.listen(() => import("./main.ts"));
 }`;
   await writeFile("dev.ts", DEV_TS);
 
@@ -506,7 +503,7 @@ if (Deno.args.includes("build")) {
       check: "deno fmt --check . && deno lint . && deno check",
       dev: "deno run -A --watch=static/,routes/ dev.ts",
       build: "deno run -A dev.ts build",
-      start: "deno run -A main.ts",
+      start: "deno serve -A _fresh/server.js",
       update: "deno run -A -r jsr:@fresh/update .",
     },
     lint: {

init/src/init_test.ts

@@ -240,5 +240,5 @@ Deno.test("init - errors on missing build cache in prod", async () => {
   const { stderr } = getStdOutput(cp);
   expect(cp.code).toEqual(1);
 
-  expect(stderr).toMatch(/Found 1 islands, but did not/);
+  expect(stderr).toMatch(/Module not found/);
 });

plugin-tailwindcss/src/mod.ts

@@ -1,20 +1,18 @@
 import type { Builder } from "fresh/dev";
-import type { App } from "fresh";
 import twPostcss from "@tailwindcss/postcss";
 import postcss from "postcss";
 import type { TailwindPluginOptions } from "./types.ts";
 
 // Re-export types for public API
 export type { TailwindPluginOptions } from "./types.ts";
 
-export function tailwind<T>(
+export function tailwind(
   builder: Builder,
-  app: App<T>,
   options: TailwindPluginOptions = {},
 ): void {
   const { exclude, ...tailwindOptions } = options;
   const instance = postcss(twPostcss({
-    optimize: app.config.mode === "production",
+    optimize: builder.config.mode === "production",
     ...tailwindOptions,
   }));